Seems to have improved slightly ($RPM_OPT_FLAGS is now used in some gcc invocations), but there are still quite a few ones where it is not. And even in the ones that do have those flags, there's still the -s which will make -debuginfo useless.
http://koji.fedoraproject.org/koji/getfile?taskID=2207299&name=build.log
Look at the gcc lines, you should find (on x86_64) these options given to it for each compilation unit: "-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic" ...and you should not find -s there.
Also, after your build is done, list files included in the -debuginfo package; if it's empty or missing some *.debug files for executables/libraries, or missing sources where they were compiled from, something's certainly wrong.

-debuginfos look ok now on a brief look. Unless you've already done it, I suggest going through the sources and verifying what the DEBUG define enables because -DDEBUG is now passed to the build. (E.g. check if it enables some features or extra output or the like that would not be desirable in end user builds.)

zfs-fuse-0.6.9-5.fc12 has been pushed to the Fedora 12 testing repository. If problems still persist, please make note of it in this bug report.
If you want to test the update, you can install it with
su -c 'yum --enablerepo=updates-testing update zfs-fuse'. You can provide feedback for this update here: http://admin.fedoraproject.org/updates/zfs-fuse-0.6.9-5.fc12

zfs-fuse-0.6.9-5.fc13 has been pushed to the Fedora 13 testing repository. If problems still persist, please make note of it in this bug report.
If you want to test the update, you can install it with
su -c 'yum --enablerepo=updates-testing update zfs-fuse'. You can provide feedback for this update here: http://admin.fedoraproject.org/updates/zfs-fuse-0.6.9-5.fc13